March 17, 2009
09:00 AM (EDT)

News Release Number: STScI-2009-12

Quadruple Saturn Moon Transit Snapped by Hubble

March 17, 2009: Saturn's comparatively paper-thin rings are tilted edge on to Earth every 15 years. Because the orbits of Saturn's major satellites are in the ring plane, too,
this alignment gives astronomers
a rare opportunity to capture a truly spectacular parade of celestial bodies crossing the face
of Saturn. Leading the parade is Saturn's giant moon Titan – larger than the planet Mercury. The
frigid moon’s thick nitrogen atmosphere is tinted orange with the smoggy byproducts of
sunlight interacting with methane and nitrogen. Several of the much smaller icy moons that
are closer in to the planet line up along the upper edge of the rings. Hubble’s exquisite
sharpness also reveals Saturn's banded cloud structure.